A Game of Thrones: 2 decks
Baratheon Power Rush
Baratheon Asshai Blitz

Total deck count: 22

That’s quite a lot of deck that’s sleeved… Of course, this doesn’t take into account of non-sleeved deck and random decks that’s passed its legality. I remembered digging up a full psychic deck for Pokemon awhile back… still intact in sleeves….. (shudder)